The invention relates to the field of television video scanning techniques and, more specifically to circular scan video formatting.
Throughout science, there are numerous processes in which data is acquired through the use of video cameras. In such applications, it is often necessary that the data be acquired within a very limited period of time. This is perhaps most important in the area of nuclear device testing, where a camera has a few milliseconds to record data before the camera is destroyed. In this situation, fast data readout is extremely important.
The conventional method of scanning a video tube is a square format, and involves reading data in one direction of a horizontal scan line, and then flying back before reading the next horizontal line. The time required for the flyback is approximately 10% of the total frame time.
Additionally, the conventional square scanning technique overscans the round target area of the vidicon camera tube in order to scan the total area of the target. This means that approximately 22% of the frame time is wasted.
In the conventional camera scanning system, a sawtooth waveform is used for horizontal deflection. The problem with a sawtooth wave is that a significant portion of data is lost due to electrical noise generated by the strong magnetic fields required for horizontal flyback. The present invention solves these problems by providing a circular scan for a camera vidicon which saves over 30% of frame time, reduces noise, reduces dead time, and captures all data because there is no flyback due to bi-directional scanning.
It is therefore an object of the present invention to provide apparatus for the circular zig-zag scanning of vidicon tubes, obviating flyback.
It is a further object of the present invention to provide apparatus for saving frame time in a vidicon by providing a circular scan in a zig-zag pattern, by not overscanning the round vidicon tube.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.